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Our future, our universe, and other weighty topics

Monday, November 17, 2014

A Scientist's Faulty Theory of Truth

In the last chapter of his
book The Truth of Science: Physical Theories and Reality,
emeritus professor of physics
Roger G. Newton advances a theory of truth. (I will call Mr. Newton
by his first name to avoid confusion with the famous physicist named
Newton.) Roger advances a coherence theory of truth. In general, such
a theory maintains that truth is whatever fits in or meshes with other
things that are regarded as true. Roger puts it this way on page 207
of his book: “The most important criterion for ascertaining the
truth of a statement is its coherence with a network of assertions
that are also regarded as true.”

But
there is a potent criticism that can be made against such a theory.
Many claimed truths can be fit in with some system of assumptions
about what is true, but do not fit in with some other system of
assumptions about what is true. So a coherence theory of truth would
seem to imply that such claimed truths are both true and false, which
doesn't make sense. For example, reincarnation fits in well with a
network of assertions made by the average Hindu, but does not fit in
with a network of assertions made by Western materialists. So
according to a coherence theory of truth, it would seem that
assertions of reincarnation or past lives are both true and false.

What
Roger clearly wants you to believe is that the real acid test for
truth is that it fit in not just with a network of assertions made by
some group, but by
Western physicists such as himself. He basically seems to be saying
that truth is whatever fits in with what him and physicists like him
tend to believe to be true.

One
problem with such an approach is that modern physical science and
scientific opinion is not a monolithic coherent “network of
assertions,” all nice and harmonious and factual. Quantum mechanics
does not agree with general relativity. Some physicists believe
passionately that string theory is the reality behind everything,
while many other physicists reject the theory as baseless. Some
physicists support the idea of a multiverse or ideas of parallel
universes. Other physicists reject such ideas with scorn. There is a
great deal of disagreement about different matters. So how can
“fitting in with what physicists think” be the acid test for
truth, when there is so much disagreement among the physicists
themselves?

Roger
takes his coherence theory to some imprudent extremes. On the same
page in which he makes the key assertion that “the most important
criterion for ascertaining the truth of a statement is its coherence
with a network of assertions that are also regarded as true,” Roger
uses this theory as a justification for rejecting evidence of the
paranormal without even examining it: “Researchers justifiably
refuse to listen to these claims, to examine them or refute them in
detail, because they are incoherent with the rest of our scientific
knowledge.” The problems with this attitude are many. First, there
is no way in which one could intelligently judge that a particular
claim was “incoherent with the rest of our scientific knowledge”
without examining the claim in detail, which Roger encourages
researchers not to do.

Secondly,
it is not obvious that most paranormal claims are “incoherent with
the rest of our scientific knowledge.” What is or is not
“incoherent with scientific knowledge” is a very debatable,
subjective matter. It is, in fact, not at all obvious that most of
the more common paranormal claims are actually incompatible with any
known laws of nature, as I argue here. What Roger encourages people
to do is to ignore classes of observations, not on any objective
basis, put purely on the very subjective judgment of whether or not
such observations are “incoherent with scientific knowledge,” a
type of judgment that might be highly influenced by sociological and
psychological factors, and our prejudices and biases.

Roger
also almost seems to imply that when you have a choice between
believing the testimony of your own senses and fitting in with a
“network of assertions” advanced by authorities, you should
ignore the testimony of your senses. I say this because he cites the
case of a psychologist who claims to have seen a celebrity in his
office long after the celebrity's death. “This is not how a
scientist arrives at truth,” intones Roger with disapproval. So if
you see something with your own two eyes, and you've never had a
hallucination before, you should ignore that, because it conflicts
with your expectations, and doesn't “fit in with the system” that
has been dogmatically taught by authorities? Wrong. Observations
should be king, regardless of whether they clash with your
expectations.

Roger's
“coherence test” for truth seems to be a type of reality filter,
with the unfortunate outcome illustrated in the diagram below:

Roger
considers for an instant the possibility that “a startling,
discordant fact, long ignored by 'the establishment,' may someday be
discovered, producing a new paradigm with its own coherence.” But
he immediately rejects such a possibility, by arguing that “the
body of scientific knowledge, however, is by now so large that this
scenario is extremely unlikely.” This is smug intellectual
complacency that is very unwarranted. From a cosmic standpoint, what
we know is very, very small compared to what we don't know. We know
of only a few planets in a vast universe which may have trillions of
inhabited planets, and we still don't understand some of the most
basic questions involving the origin of the universe, the origin of
cosmic structure, the origin of life, and the origin of
consciousness. We are puzzled by a thousand mysteries of time, space,
and Mind that we haven't figured out. An extraterrestrial species
might look at us as we might look at little children playing at the
sea shore, trying to figure out the ocean from the waves and the
shells. Looked at from such a perspective, our knowledge of things is
very fragmentary and very small, not “so large” as Roger argues.
So the “new paradigm” scenario Roger mentions is very plausible,
not “extremely unlikely” as Roger argues.

One
problem with Roger's approach is that only part of the “network of
assertions” made by modern physicists is actually fact. There is
also a great deal of theory being asserted, much of it wild and
speculative (physicists these days love to advance all kinds of
extremely weird theories). Then there are also quite a few assertions
that come under the category of “widely held assumptions” that
have no direct scientific support, such as claims that the universe
is entirely random, or claims that all consciousness can be explained
by brain activity (no one has ever published a scientific paper
proving either assumption). It is a nightmare to sort out which
parts of the modern scientist's “network of assertions” is fact,
which is theory, and which is personal opinion advanced more out of a
sociological kind of peer group conformity than scientific necessity.
So how could “coherence” with such a network of assertions be a
reliable basis for judging truth – particularly since “coherence”
is a vague, wooly, subjective term, incapable of being objectively
measured, without any of the precision that scientists like to have?

It's
easy to imagine examples that show that a coherence theory of truth
doesn't work. Let us imagine that some astronomical analysis software
has a bug, and because of the bug a scientist who is analyzing a
distant solar system concludes mistakenly that such a solar system
has an Earth-sized planet. Then let us imagine that a second
scientist in another country uses the same buggy software to analyze
that distant solar system, and therefore draws the same incorrect
conclusion that such a solar system has an Earth-sized planet.
According to a coherence theory of truth, the second scientist must
have stated a true assertion – because his assertion not only has
excellent coherence with other scientists finding Earth-sized
planets, but also good coherence with the previous scientist
concluding that there was an Earth-sized planet at the particular
distant solar system the second scientist analyzed. But, in fact, the
second scientist has not made a true conclusion, because there is no
Earth-sized planet in that particular solar system.

There
is a much better and simpler theory of truth than Roger's. It is
called the correspondence theory of truth. According to that theory,
an assertion is true simply if it corresponds to a factual reality.
So even if the entire world thinks that a particular celebrity is
dead, if I assert that this celebrity is alive and well and in Chicago, and that celebrity is alive and well in
Chicago, then my statement is true; otherwise it's
false. The truth or falsity of my statement in no way depends on
whether it agrees or disagrees with a “network of assertions”
being made across the world and the Internet.

Roger
takes a weak poke at this correspondence theory of truth, claiming
that it does not work well with universal statements of truth such as
“matter is made up of atoms and molecules.” This is not at all
correct. In this particular case, the correspondence theory of
truth says that such an assertion is true if matter is actually made
of atoms and molecules, and false if matter is not made up of atoms
and molecules. That works just fine.

The
correspondence theory of truth is a far more sensible theory of truth
than the coherence theory of truth advanced by Roger. When it comes
to the truth of a matter, what matters is facts, reality, and
observations, not fitting in with the assumptions and taboos of
revered authorities, whether academic or ecclesiastical.

Postscript: I criticize here merely one part of Mr. Newton's book, a work which makes many sound and valid points.

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All posts on this blog are authored by Mark Mahin, and are protected by copyright. Copyright 2013-2014 by Mark Mahin. All rights reserved. Any resemblance between any fictional character and any real person is purely coincidental.